Fig 15 2 ALVIN after 10Vj months at 5.052-toot depth (WHOI) 



Submersible: DEEPSTAR 4000 Date: 

 May 1967 Reference (1) 



Incident: DEEPSTAR 4000 was per- 

 forming a series of test dives at Panama 

 City, Florida. During launch, the vehicle was 

 hoisted off the deck of its support ship and 

 swung over the side. Some 5 feet in the air, 

 the quick-release launching hook unexpect- 

 edly opened and dropped the vehicle into the 

 water. The events surrounding the unex- 



pected release were examined. As far as 

 could be determined, the release line was not 

 fouled nor had it been accidentally pulled. 

 Examination of the hook showed that under 

 certain conditions a mechanical open/closed 

 indicator could point to closed when, in fact, 

 the hook was only partially latched. It was 

 concluded that the visual check of the hook 

 showed a "closed" hook and the OK to launch 

 was given. The hook, in fact, was only par- 

 tially closed. It held the vehicle load (18,000 



693 



